125+675÷25×18
=125+486
=611
13.2-（3.2-2.4-0.45）
=13.2-3.2+2.4+0.45
=10+2.85
=12.85
4.5×0.5＋5.5÷2
=4.5/2+5.5/2
=10/2
=5